I don't know the general opinion, but here is mine. Half of it is relatively useful, the other half is not. The most useful half is a nice description of the gods, titans and their respective followers and planar realms. There is plenty of material here which I used for most of my games. Some of the info here repeats with other books however (notably the Player's Guide to Clerics and Druids and Edge of Infinity), but it's hard to tell how much. There are a couple of spells and domains that were nice back in the day, but depending on your system of choice it can be outdated ^^ The other half (a small half, not even a third probably, but it sure seems like a lot of space) is the stats for all avatars, heralds and pages for the gods and demi-gods. It seems a whole waste of space, I've never used it, but well, it is indeed a Deities and Demi-Gods-style book, so I guess it was mandatory to have this kind of stuff.

All of the non-game stats portions of the book are very helpful in furthering the detail one can add to things like religious characters and organizations.

The heralds presented with stats could be useful, since those are the things most likely to be interacted with in a way that their stats might become relevant... but the CR 40-something stats for avatars of the gods only serve to waste space because characters able to face them in combat and have a hope of survival aren't at all common for people to play (I can count on one hand the number of campaigns throughout the last few decades I've heard of or participated in that reached that point), and if characters of normal levels (20th or lower) are facing off against avatars of the gods, their stat-block might as well be replaced with "Even if you roll well, you lose."

I guess someone could use the stats to have the avatars of the gods square off against each-other, but I'm not sure that rolling that out and following the game rules, rather than just narrating it as awesomely as you can, improves that situation.

It's weird that though I almost never use the game rules on this book, I find it one of my most useful books. It provides me with the basic grist on the primary antagonists of the setting--who they are, how they operate, what they want.